Workpieces and particularly those formed as castings often have interior chambers formed therein which have only limited accessibility. Such interior chambers are often shaped and sized so that portions thereof are of significantly larger cross section than any access opening which communicates therewith, and such interior chambers also often include passages or the like which communicate with or project transversely from a main chamber or passage, and as such direct communication with these transverse passages from the access opening is oftentimes difficult or impossible. It is usually necessary to attempt to effect at least some treatment of the walls which define the boundary of the interior chamber in an effort to improve the smoothness and finish thereof, and/or effect removal of debris which may be loosely or firmly attached thereto. This is particularly true when the workpiece is formed as a casting since the core used for defining the interior chamber during the casting process breaks down quickly after pouring and forming of the workpiece, and the material defining the core has to be removed through the access opening, but some material frequently becomes trapped in the interior chamber and/or adheres to the surrounding walls so as to create a poor quality surface.
At the present time, the cleaning of the interior chambers of workpieces of this type involves various techniques such as shaking the workpiece on a vibrator, or injecting streams of fluids such as air or water into the chamber in an attempt to dislodge debris from the chamber or from the walls thereof. This technique, however, is relatively ineffective with respect to creating any significant improvement with respect to the smoothness or quality of the boundary walls.
Because of the difficulties associated with cleaning and treating interior walls of chambers defined within workpieces such as castings, in many instances flexible brushes are inserted, often manually, into the chamber to treat the boundary walls thereof. This technique is partially effective for those boundary walls which communicate with and are accessible from the access opening, but is of little value with respect to those walls which are associated with unusual shapes or transversly projecting regions of the interior chamber. Further, this technique is time consuming and inefficient.
Accordingly, it is an object of this invention to provide an improved apparatus and process which permits effective and efficient surface treating of boundary walls associated with interior chambers of workpieces, particularly castings, whereby the finished walls can have improved surface quality and the overall interior chamber can be cleaner and less likely to contain unwanted debris, and wherein the process is effective for interior chambers having complex configurations including passages remote from but interconnected to a main passage which communicates with an access opening, and which permits substantially automated or partially automated handling of workpieces and cleaning and surface finishing of interior chambers so as to greatly improve the cost effectiveness and efficiency associated with the manufacture and use of such workpieces.